Gas streams often carry particulate material therein. In many instances, it is desirable to remove some or all of the particulate material from a gas flow stream. For example, air intake streams to engines for motorized vehicles or power generation equipment, gas streams directed to gas turbines, and air streams to various combustion furnaces, often include particulate material therein. The particulate material, should it reach the internal workings of the various mechanisms involved, can cause damage thereto. It is therefore preferred, for such systems, to remove the particulate material from the gas flow upstream of the engine, turbine, furnace or other equipment involved. A variety of air filter or gas filter arrangements have been developed for particulate removal.
Conventional filter elements will typically employ either a pleated filter media, a depth filter media, or a fluted filter media.
Various examples of filter elements employing a fluted filter media are illustrated in U.S. Pat. No. 6,190,432 to Gieseke, et al., U.S. Pat. No. 5,820,646 to Gillingham, et al., U.S. Pat. No. 3,025,963 to Bauer, and U.S. Pat. No. 4,589,983 to Wydevan, each of which is incorporated herein by this reference. The '646 and '983 patents illustrate, for example, filter elements with an integrally formed impervious outer skin with axial flow therethrough. Improvements to fluted filter arrangements are disclosed herein.
Various examples of pleated filter elements are disclosed, for example, in U.S. Pat. No. 6,447,567 to Ehrenberg, U.S. Pat. No. 5,484,466 to Brown, et al., U.S. Pat. No. 5,238,474 to Kahlbaugh, et al., and U.S. Pat. No. 4,720,292 to Engel, et al., each of which is incorporated herein by this reference. As illustrated in each of these aforementioned patents (for both fluted and pleated filter patents), filter elements will typically incorporate a form of an external seal that is adapted to seal the filter element against a housing, mounting base or duct, into which the filter is mounted. As is exemplified by these patents, it is also known to incorporate a foamed urethane seal to provide an external seal. Improvements to such seal arrangements are also disclosed herein.